The floor sets a minimum effective rate. If your gain would otherwise be taxed above 30%, nothing changes - you pay your marginal rate. If your rate on the gain would fall below 30%, the floor tops it up to 30%. Critically, it is calculated on the gain itself, independently of the rest of your tax position. That removes a series of familiar strategies from the table:

• Realising in a low-income year no longer helps. Deferring a sale to a year when you expect a lower marginal rate will not get you below 30% on the gain.
• Large concessional super contributions no longer help. Catch-up contributions and the two-year contribution-reserving strategy can reduce your taxable income - but not the tax on the gain below 30%.
• Even substantial tax losses won't help. Carried-forward revenue losses and other deductions can shelter your other income, but the gain itself is still taxed at a minimum of 30%.

There is one important exception. People receiving means-tested income support - such as the Age Pension or JobSeeker - are exempt from the floor in any year they receive a payment. For them, the familiar strategies still work: realising in a low-income year, making deductible super contributions and applying tax losses can each reduce the tax on a gain, exactly as they do today.

First, the 30% applies to the net gain, not the headline figure. Indexation lifts your cost base, and capital losses still reduce the gain before the floor applies - so the base it bites on is smaller than the raw profit.

Second, the new regime applies to assets you already own. Growth accruing up to 1 July 2027 keeps the existing 50% discount under the transitional rules, but all growth from 1 July 2027 onwards - even on long-held assets - is caught.

The real levers now are indexation, capital losses and the timing of a sale relative to 1 July 2027 - not the income-shifting strategies that used to work.